/*
 * Copyright 2009-2013 by The Regents of the University of California
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * you may obtain a copy of the License from
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package edu.uci.ics.pregelix.runtime.touchpoint;

import edu.uci.ics.hyracks.api.dataflow.value.INormalizedKeyComputer;
import edu.uci.ics.hyracks.api.dataflow.value.INormalizedKeyComputerFactory;
import edu.uci.ics.pregelix.api.graph.NormalizedKeyComputer;

/**
 * This class wraps the user-defined normalized key computer to calculate the normalized
 * key of vertex ids.
 * 
 * @author yingyib
 */
public class VertexIdNormalizedKeyComputerFactory implements INormalizedKeyComputerFactory {
    private static final long serialVersionUID = 1L;
    private Class<? extends NormalizedKeyComputer> nmkComputerClass;

    public VertexIdNormalizedKeyComputerFactory(Class<? extends NormalizedKeyComputer> nmkComputerClass) {
        this.nmkComputerClass = nmkComputerClass;
    }

    @Override
    public INormalizedKeyComputer createNormalizedKeyComputer() {
        try {
            final NormalizedKeyComputer nmkComputer = nmkComputerClass.newInstance();
            return new INormalizedKeyComputer() {

                @Override
                public int normalize(byte[] bytes, int start, int length) {
                    return nmkComputer.getNormalizedKey(bytes, start, length);
                }

            };
        } catch (Exception e) {
            throw new IllegalStateException(e);
        }
    }
}
